Port operator Asciano has finally struck a pay deal with the Maritime Union of Australia after almost 20 months of negotiations and strikes.

Earlier this week the union and Asciano, which owns stevedoring company Patrick, began formal negotiations before Fair Work Australia.

The two sides have agreed to a deal that will see Patrick's container terminal workers receive pay rises in return for commitments towards improved productivity.

MUA national secretary Paddy Crumlin says both parties are pleased with the outcome.

"You don't get agreement unless you're happy and we're happy that actually it was agreed and that both parties got what they wanted," he said.

"We wanted surety with safety, stability and ability to compete under fair terms of employment.

"The company got what they wanted - the ability to manage their affairs, the high productivity and efficiency that's required and of course they're just as committed to safety as we are."

The agreement still has to pass an employee ballot, but the threat of another lock-out on Patrick's wharves - and the millions of dollars in disruptions that would cause the economy - looks to have been averted.

In a statement, Asciano said the resolution was in no small part due to the recent intervention of Workplace Relations Minister Bill Shorten.

"We would like to thank the Minister for his persistent efforts and constructive role in engaging with the leaders of both parties to enable an agreement to be reached," it said.

Mr Crumlin agrees Mr Shorten's intervention was key to breaking the deadlock by convincing the parties to go to conciliation and arbitration at Fair Work Australia.

"Particularly after a long time it begins - a bit like trench warfare - people get in an area of adversarial negotiations where it's very hard to break that, because fatigue sets in," he said.

"And the Minister has a very persuasive style about him and intervened at a critical point - let's face it, that was a pretty important intervention because three or four days later we've now got an agreement."

'Weakness in system'

But some experts say the need for ministerial intervention shows the current system has a problem when there are powerful employers and unions unwilling to compromise.

Professor Andrew Stewart, who teaches industrial law at the University of Adelaide, says change is needed.

"I do think it betrays something of a weakness in the system if it's going to take personal intervention from the workplace relations minister," he said.

"So the question that this dispute throws up, and the same question that the Qantas dispute threw up, is do we want to have a system in which disputes can run for a long time or only be resolved when one party hits the nuclear button?

"In the case of Qantas it took a lock-out. In the case of the Asciano dispute, there was a threat of a lock-out. Should it be easier than it currently is for one or other party, or indeed for the independent umpire, to step in and say enough's enough - let's resolve this dispute through arbitration?"

Primary problem

Australian Chamber of Commerce and Industry chief executive Peter Anderson says it is militant unions that are causing delays in striking enterprise agreements.

"Fair Work Australia's not the problem when it comes to collective bargaining," he said.

"The primary problem is the attitude of some unions who are seeking to stretch the envelope with claims and then to use what the government has presented to unions - very attractive powers - to put economic pressure and use economic coercion to get their way."

But Professor Stewart says the collective bargaining regime is almost the same as it was under the Howard government, and Australia has some of the highest restrictions on strike action in the developed world.

"The laws on industrial action that currently apply are essentially the Howard government's laws," he said.

"And the idea of having a system that gives primacy to enterprise-level bargaining over compulsory arbitration of disputes is something that's been a constant for the last 20 years under both major parties."